Scale distortion is very practical when differences are either miniscule or astronomical. A poster of our solar system where the sun and planets are at scale would look like a black piece of paper with a tiny white dot in the center.
From what I remember there are various different depictions for different purposes. Most are just showing order and what they look like visually so the precise scale is a detriment and skipped. Most of the solar system to scale things I've seen in person are multiple blocks long so the planets are a reasonable size, there's not really a reasonable way to print a to scale in both size and distance in a book.
If you're being accurate in both distance and size scales your smallest dot would be Mercury and the distance from the Sun to Neptune (assuming this is a modern text book and we're dropping Pluto) would be 922000 of those dots. Even if we print it at the higher 1200 PPI [0] used for line art that's ~770 inches, that's a huge image far larger than any reasonable book. You could do it with a fold out but that's it's own expense and unreasonable for inclusion in an actual textbook.
That's why I was saying doing both accurate size and distance is difficult for the solar system.
[0] Images are more often printed at 300 PPI but I'm giving you the best case scenario here.
Yep, it looks much more dramatic than that is. A realistic scale would make objects invisible, unfortunately. So I can see why they make things bigger than they are.
The reason why there are so few incidents is that low earth orbit is simply a very large volume of space. It would be a mistake to think of it in 2D terms, it's a few hundred km in height and it has an area even at the lowest orbit that is larger than the surface of the earth. The total volume is orders of magnitudes larger than all our oceans combined.
So what's the chance of 2 out of a few hundred thousand things floating around in random orbits crashing into each other? It's not zero. But it's close enough to zero that it's very rare. But high enough that people worry about it somewhat. Obviously some orbits are quite congested and having a lot of debris scattering all over the place after a collision makes things worse. And the speeds at which things are moving around would cause some high energy collisions even for small objects.
> that there are city sized satellites flying above them
I don't think this is so much the issue, as much as that I didn't think about it.
I opened it and my first thought was wow, it's packed up there. Didn't consider the size of the things it's displaying relative to things on the surface.
There is certainly some merit in ensuring that first impression is accurate.
> I opened it and my first thought was wow, it's packed up there
I mean, it is also pretty packed up there. Considering that a rocket launch has to give every object up there a decently wide berth, it's still a shit ton of moving obstacles that have to be constantly taken into account - the relative size of the gaps between them doesn't really change that equation much.
Yes. I once overheard a flat earther argue that spare reporting is fake because there are supposed to be tens of thousands of satellites, yet photos from the ISS don't show any of them.
It's less illusion and fantasy and more code for "what I think." If you notice, it's only uttered by people who believe their own reasoning should be automatically accepted as truth. Ego leaves no room for doubt or embarrassment.
“any accurate depiction of elevation would be indistinguishable from a flat map at that scale. The coast-to-coast measure of the US is a bit under 3000 miles, while the highest elevation in the continental US is a bit under 4½ miles above sea level, so in a 1000-pixel map, that would translate to a 1–2 pixel height for Mt Whitney which is the highest point in the contiguous United States.”
and also
“the difference in elevation between Everest and the Marianas Trench is less than the bulging of the earth from its rotation. And that amount is less than you might guess. If we scale the earth down to a diameter of one foot (which would be bigger than my childhood globe), the bulge would be 0.04in or roughly 1mm. Good luck distinguishing your oblate spheroid from a sphere with those numbers.”
Yes and to be clear on what "practical" means here. If there's a mountain between origin-destination for a road trip it's relevant to highlight it. In the case of orbits the objects may be small but they're very fast and very dangerous.
I think calling them dangerous is even a bit misleading as they're well tracked. Some of them even autonomously precisely position themselves rather than be on ballistic trajectory.
Only the largest objects are trackable. Objects in the 1-10 cm range are large enough to destroy satellites instantly but too small to track. Obviously any visualization will only show known objects.
This explains both why "dangerous" is accurate, and why autonomous avoidance based on tracked objects (ala Starlink) is 'necessary but not sufficient.'
An honest visualization to scale would just have the satellites being faint dust smaller than your pixels? Wouldn't be useful. But agreed that if you could zoom in and visualize the actual scale that'd be interesting and informative. Would be cool seeing the difference in satellite size. But would be less useful as a broader visualization of LEO.
Objects are not to scale for unavoidable reasons, but time is also not to scale. These two effects tend to cancel out.
People look at this visualization for what, 60 seconds? But the issue is that objects are zooming around up there for years-to-centuries.[0] The total volume of space swept out is massive.
Invariably the "not to scale" comments always get pointed out every time this is posted, but the temporal distortion (which makes people underestimate collisions) is never mentioned. Unless I mention it[1] of course... ;)
There's a much much better educational ESA video[2] which addresses some of the misconceptions in this thread, found via (of all places) Don Kessler's personal website.
---
If you want an expert perspective on orbital debris (vs..... whatever these HN threads always turn into :D ) I highly recommend you check out NASA Johnson's Orbital Debris Quarterly.[3]
[2] As this video points out, collisions scale as density squared, which is why all major collisions have happened near 80 degrees latitude: http://www.youtube.com/watch?v=RvZ3Lr-Tj6A
Some kind of a relative velocity at the closest approach or a collision probability overlay would be way more useful to have than proper scale. That would make it immediately clear that lazy well-kept orbits like GEO are much safer than e.g. 567km SSO at the poles. Or some color coding for the apparent magnitude.
While I totally agree with the logic, this particular visualization might mislead unsuspecting viewers into believing that our LEO is almost fully saturated. In reality, the satellites are so small that they would miss each other even if placed on the same orbit.
A true-to-scale visualization would however be entirely misleading for everyone since it would be completely empty. Just look up in the sky at a clear sky. You would hardly see a single satelite and a visualization on a computer screen would show even less due to pixel size.
Actually the Kesler syndrome, a space debriss cascade is a very real threat and a real concern. I suggest an interview with the commander of the space control quadron in a radiolab episode "Little Big Questions"
> the Kesler syndrome, a space debriss cascade is a very real threat and a real concern
It’s also widely misunderstood.
The risk is in trashing specific orbits. Below 600 km, that would mean certain orbits are too polluted to use for a few months to years. (A dense, compact object above 600 km could stay lofted for decades to over a century. But again, only within a predictable volume.)
It's actually mostly because we allow objects to fly too high. Small height differences have a huge difference in orbital lifetime (and therefore risk).
well... Out sky is full of satellites.
Granted, there's a lot of empty space in between. But ask any (hobby) astronomer and they'll start a rant about starlink :-P
If anyone is curious, as I was, about the large red shapes on the map, those are the beams of the object tracking/measurement sites. They correlate with the maps at [0]. I was actually pretty blown away when I started reading that page. Apparently those stations can measure <10cm-sized debrisin orbit. What?! Amazing.
The instrument is the particular radar. They usually have two at each location. Each radar is essentially a linear phased array that creates multiple possible beam locations in the radar plane. They light up a beam as a satellite passes through in order to collect measurements. TLDR an instrument has multiple beams.
For those who don't know, Leo Labs operates a commercial version of NORAD radar sites that track satellites and debris.
If you're a satellite operator looking to avoid conjunctions, then buying additional measurements helps reduce uncertainty (which is often needed in order to decide if you should conduct a maneuver).
Three now, Starlink Group 9-3 launch failed in July last year. After the failure, the launch hold was cleared in 13 days, which has to be a record of some sort.
If you zoom in, about one in 20 is tumbling around path randomly, and its description is “Rocket body”. But it’s not on “Debris” layer.
I wonder why it doesn’t qualify for debris if it looks likely uncontrollable.
Just a reminder to everybody that we are competitively sprinting towards the brick wall of Kessler Syndrome by building out mega-constellations between about 600km and 1600km, sacrificing humanity's future in order to save a small amount of money right now using lower altitude orbits.
Even Starlink is arguably flying too high, but the attempt to compete with them at 1000km where satellites will be causing secondary and tertiary debris events for literally millennia, makes that look sensible.
Specific orbits (732km with a 28 degree inclination and 130 degree longitude of the ascending node), but impacts also instantaneously spread debris out over anything close to any of those numbers (700-760, 27-29, 125-135); most debris get spread not in a normal distribution but in a bimodal distribution between the orbital elements of the two impactors, with an additional perimeter of debris kicked out with some random modest dV in every direction from the explosion according to how much impact energy they absorbed. To start with.
But then, debris start to decay, and they decay unevenly, polluting all orbits lower than that. As this debris spreads to a crowded lower orbit it generates additional collisions.
Orbits are cleared to lower orbits according to mass cross section at roughly 10x the rate for every 100km altitude drop. So everything that decays from an accumulation of higher orbits has to eventually pass through a 300km circular orbit, but it's relatively safe because it spends so little time there.
Going full exponential cascade at 1000km might increase the number of impactors by a millionfold, though, which then proceed to rain down over the years on lower orbits.
Starlink is just under 600km in order to target a specific voluntary threshold of 25 year decay. Most of their finished birds are going to make around 5 years without propulsion or impacts.
Three things about that -
Profitability generates competition, which may or may not respect precedent. Right now Starlink is only really worried about collisions with other parts of Starlink. We cannot afford a Starlink-inspired future to happen at 600km.
Debris generating events can spin out an object with much higher cross sectional mass than an intact satellite. Think of it in terms of what we use drag for on Earth, like a kid building kites. A heavy metal bolt works worse as a kite than a long thin panel.
These calendar decay timelines are blind to density. If there are a billion satellites with a natural lifespan of 5 years flying at 551km then they are going to go into an exponential cascade in a matter of weeks. If you plan to launch very large constellations, you need very fast decay timelines to keep that safe. It is much safer at very low altitude. There is decay 'room' for >10x as many satellites at 300km as at 400km, and >10x as many at 400km as at 500km, and >10x as many at 500km as 600km.
...
It would also be nice to set aside something for manned spaceflight. Unlike with a satellite collision, if a pressure vessel gets penetrated everybody dies and nobody wants to go back. The ISS and Tianhe are going to have to deal with debris risk slowly raining down from a collision at 971km.
This reminds me - I've been looking for an app, website or tool that can predict or visualize the location of any satellite up to a week out. Most softwares show only the intersection times of predicted orbits with fixed locations on earth, i.e. for telescope visibility.
The visualisation is cool. I've never seen the debris fields visualized before. They look like scars. Might be neat to see a viz including the geo synchronous and sun synchronous orbits. Should show up as seemingly dense, but far away.
Those large red blobs are not visualizations of debris fields. You can toggle them off as "instruments", and debris is actually toggled off by default.
If you're looking for something real-time, I'd recommend checking out NASA's "Eyes on the Solar System" visualizer (not as comprehensive but still pretty cool):
Nice to see United Kingdom using a predictable trajectory. Dismayed by so many other nations just crapping all over the planet without consideration though. The lack of foresight is frustrating.
They're not really crapping all over. Orbits at different altitudes rotate around the planet from precession so any satellites spread out randomly over time.
This is the opposite of depressing. Look what we've been able to do! Each of those have/had a purpose and reason for being there and we've gotten tremendous benefit from satellites in space.
In the search box, input "ISS" and filter by perigee (min: 380; max: 500). You should see the name of one of the modules of the ISS, such as "ISS (Zarya)" [0] or "ISS (Nauka)" [1]. If you can't find it on the visualisation at first, you can get its current location at https://isstracker.pl/en .
Starlink satellites are in low enough orbit to decay on very short timescales. More worrisome are Russian satellites in high / very long lived orbits that tend to spontaneously explode.
Not just Russian. There have also been a few cases recently where spent Centaur upper stages -- which were thought to have been completely passivated -- broke apart for unknown reasons. These were in a geosynchronous transfer orbit (with apogee near geosynchronous orbit, perigee down near LEO) so the debris won't decay any time soon.
Upper stages breaking apart is kinda expected. It's a rocket, and it has rocket fuel (explosives) on board. Derelict spy satellites, on the other hand, shouldn't be just going kaboom for no reason. But the Russian ones do.
As noted by another poster, prior to the recent ASAT tests, one of the largest sources of junk was old Soviet nuclear-powered satellites leaking coolant and/or having their pressure vessels explode. Mind you these are actual nuclear reactors, not RTGs.
No, all residual fuel (and anything pressurized) should have been vented after the last burn and there shouldn't be anything left on board with enough energy to cause it to break apart.
(May I ask what definition of ‘passivate’ you are applying here? Even allowing for flexibility in the definition or autocorrect, and applying context, I can’t fathom what is intended to be conveyed by ‘upper stages - which were thought to have been completely passivated’)
> "The incident is the fourth time a Centaur upper stage has broken up since 2018. In the earlier three cases, the breakups created hundreds of pieces of debris, but no known collisions. That has raised questions about a potential design flaw with the stage or a failure to “passivate” the stage by venting propellant tanks and draining batteries, removing energy that could cause a breakup."
It's not the only one, just the most recent. A collision can't be ruled out, but there is a frequent tendency of old, retired Russian satellites just exploding for no reason:
Before the Chinese A-Sat weapon tests, the #1 source of space junk was radioactive coolant leaking from old Soviet nuclear reactors in space (not RTGs, literally nuclear reactors)
"The Soviet Union has been flying nuclear power sources in space since about 1965. For the most part these nuclear power sources have been low-power nuclear reactors using a thermoelectric conversion principle."
The thing 'rebelgecko is alluding to is specific, and fascinating! The coolant in these space reactors is a molten metal (low-melting point sodium-potassium eutectic). When they leaked in the space vacuum, the liquid dispersed into a large number of small, metal spherules, which formed rings around Earth. Because the spherules are metallic and smooth, they're (comparatively) easy to track by radar, from Earth.
It may comfort you to hear that the Starlink satellites are tiny in comparison to the vastness of their orbit – the visualization makes them appear larger than they are, so you can see them clearly – and that they’re low enough that they’ll naturally de-orbit and burn up in the atmosphere after about 15 years even without using their maneuvering thrusters.
They’re providing worldwide rural broadband, and according to the FAA they’re doing so in a way that’s careful and responsible about space debris and collision avoidance. Is disgust truly warranted in this case?
We've banned this account for using HN for ideological battle about a single topic. This is against the HN guidelines. Please stop registering accounts for posting about this topic and breaking the guidelines. Other community members are noticing this activity and pointing it out to us.
It's more that Golden Dome is taking advantage of the architecture that Starlink has proved to be realistic. It will use separate satellites managed by the Space Development Agency (Tranche 0 consisting of proof of concept stuff launched a while ago
Sure, that's why satellite constellations were developed. The thing people might not appreciate is that it's still the main driver for these companies to develop them.
> it's still the main driver for these companies to develop them
It’s not. Not by a long shot. Like, OneWeb and Planet Labs are not secretly ABM projects.
It’s a motivation. One that until recently didn’t pay the bills. But it’s never been the motivation for any commercial constellation so far. (Starshield comes close. But I wouldn’t say ABM is even in the top three military motivations for that project.)
That's not true. Starlink was developed for its stated purpose. It's a conspiracy pushed by Russian plants that it's for missile defense. A lot of information on that wiki page is made up. Like the constant talk of griffin.
Griffin did not fund SpaceX. He does not have any money. And yes Griffin, among several other people, accompanied Musk to Russia as advisors for his private plan to buy rockets to send a mini-greenhouse to Mars. The failure to make a deal is what precipitated the creation of SpaceX. Elon offered Griffin the position of chief engineer at SpaceX, but Griffin refused.
Objects not to scale. Not even close, and no mention of it (that I saw).
Graphing scale honestly is extremely important. A lot of people are convinced our sky is full of satellites because of visualizations like this.
Scale distortion is very practical when differences are either miniscule or astronomical. A poster of our solar system where the sun and planets are at scale would look like a black piece of paper with a tiny white dot in the center.
"A poster of our solar system where the sun and planets are at scale would look like a black piece of paper with a tiny white dot in the center."
Yes. And therefore a very valuable visualisation of reality.
Visualisations at scale are nice and useful, too, but they are misleading if the actual sizes are never shown to the target audience.
From what I remember there are various different depictions for different purposes. Most are just showing order and what they look like visually so the precise scale is a detriment and skipped. Most of the solar system to scale things I've seen in person are multiple blocks long so the planets are a reasonable size, there's not really a reasonable way to print a to scale in both size and distance in a book.
"there's not really a reasonable way to print a to scale in both size and distance in a book."
There is. Just one picture of small dots in lots of black space can give perspective, .. next to the other visualisations. And some books do that.
Did you check the actual dimensions it would be?!
If you're being accurate in both distance and size scales your smallest dot would be Mercury and the distance from the Sun to Neptune (assuming this is a modern text book and we're dropping Pluto) would be 922000 of those dots. Even if we print it at the higher 1200 PPI [0] used for line art that's ~770 inches, that's a huge image far larger than any reasonable book. You could do it with a fold out but that's it's own expense and unreasonable for inclusion in an actual textbook.
That's why I was saying doing both accurate size and distance is difficult for the solar system.
[0] Images are more often printed at 300 PPI but I'm giving you the best case scenario here.
I was talking about rough illustrations with picture in picture (with a lense) to give a basic idea. But I do remember maps that could be folded out.
Most people have never seen a visual of earths layers to scale. The crust, even when thin, is usually not to scale
Yep, it looks much more dramatic than that is. A realistic scale would make objects invisible, unfortunately. So I can see why they make things bigger than they are.
The reason why there are so few incidents is that low earth orbit is simply a very large volume of space. It would be a mistake to think of it in 2D terms, it's a few hundred km in height and it has an area even at the lowest orbit that is larger than the surface of the earth. The total volume is orders of magnitudes larger than all our oceans combined.
So what's the chance of 2 out of a few hundred thousand things floating around in random orbits crashing into each other? It's not zero. But it's close enough to zero that it's very rare. But high enough that people worry about it somewhat. Obviously some orbits are quite congested and having a lot of debris scattering all over the place after a collision makes things worse. And the speeds at which things are moving around would cause some high energy collisions even for small objects.
"Floating around" isn't accurate. "Screaming around at 8 kilometers per second" is more accurate.
The fact that debris objects swee through an enormous volume of space per year (and are up there for years to centuries) makes it much worse.
https://commons.wikimedia.org/wiki/File:Orbital_Debris_Lifet...
http://www.youtube.com/watch?v=RvZ3Lr-Tj6A
Do you think that some people look at this visualisation and leave with the impression that there are city sized satellites flying above them?
> that there are city sized satellites flying above them
I don't think this is so much the issue, as much as that I didn't think about it.
I opened it and my first thought was wow, it's packed up there. Didn't consider the size of the things it's displaying relative to things on the surface.
There is certainly some merit in ensuring that first impression is accurate.
> I opened it and my first thought was wow, it's packed up there
I mean, it is also pretty packed up there. Considering that a rocket launch has to give every object up there a decently wide berth, it's still a shit ton of moving obstacles that have to be constantly taken into account - the relative size of the gaps between them doesn't really change that equation much.
Yes. I once overheard a flat earther argue that spare reporting is fake because there are supposed to be tens of thousands of satellites, yet photos from the ISS don't show any of them.
Absolutely. Common sense and critical thinking is less common than you may think.
That's in part because "common sense" is an illusion and fantasy.
It's less illusion and fantasy and more code for "what I think." If you notice, it's only uttered by people who believe their own reasoning should be automatically accepted as truth. Ego leaves no room for doubt or embarrassment.
Yeah but I caught myself 3 seconds later.
Enough HN users are retarded enough that they'll start talking about Kessler syndrome because they don't understand what they're looking at.
My dude, some people look up at the sky and see airplane contrails and clouds and conclude all sorts of outlandish nonsense.
Proper scale makes the visualization impractical. I wrote about this with respect to a US map showing mountains on my mailing list: https://dahosek.substack.com/p/one-million-stories
“any accurate depiction of elevation would be indistinguishable from a flat map at that scale. The coast-to-coast measure of the US is a bit under 3000 miles, while the highest elevation in the continental US is a bit under 4½ miles above sea level, so in a 1000-pixel map, that would translate to a 1–2 pixel height for Mt Whitney which is the highest point in the contiguous United States.”
and also
“the difference in elevation between Everest and the Marianas Trench is less than the bulging of the earth from its rotation. And that amount is less than you might guess. If we scale the earth down to a diameter of one foot (which would be bigger than my childhood globe), the bulge would be 0.04in or roughly 1mm. Good luck distinguishing your oblate spheroid from a sphere with those numbers.”
That would also mean that whenever I see a flat geo image, it could be a heightmap from a creator that was just too honest about scale.
Yes and to be clear on what "practical" means here. If there's a mountain between origin-destination for a road trip it's relevant to highlight it. In the case of orbits the objects may be small but they're very fast and very dangerous.
I think calling them dangerous is even a bit misleading as they're well tracked. Some of them even autonomously precisely position themselves rather than be on ballistic trajectory.
Only the largest objects are trackable. Objects in the 1-10 cm range are large enough to destroy satellites instantly but too small to track. Obviously any visualization will only show known objects.
This explains both why "dangerous" is accurate, and why autonomous avoidance based on tracked objects (ala Starlink) is 'necessary but not sufficient.'
> Proper scale makes the visualization impractical.
So lie?
You can see from the comments most Hacker News users can't handle the abstraction.
Your blog post is great, but most people don't know the Earth is a perfect sphere or simple things like the sun is white, the real "Don't Look Up"
Universities have become pop culture, they are Gravity (2013), not 'science', whatever that word means now.
We cross mountains so that abstraction has a use, here it is for the nihilist crowd.
> So lie? Any 'visualisation' is a 'lie'.
If you look at google maps you'd think the distance between New York and Los Angeles is about 3 inch (depending on your zoom factor).
If you manage to grasp that abstraction, you might think the roads are about 5 miles wide.
etc etc.
where to draw the line.
> If you look at google maps you'd think the distance between New York and Los Angeles is about 3 inch (depending on your zoom factor)
But not twice the distance between Sacremento and San Jose.
> Your blog post is great, but most people don't know the Earth is a perfect sphere
Typo? The Earth is a an oblate spheroid, slighly flattened out at the poles and wider at the equator.
> So lie?
You're going to enjoy the log scale
[dead]
An honest visualization to scale would just have the satellites being faint dust smaller than your pixels? Wouldn't be useful. But agreed that if you could zoom in and visualize the actual scale that'd be interesting and informative. Would be cool seeing the difference in satellite size. But would be less useful as a broader visualization of LEO.
Objects are not to scale for unavoidable reasons, but time is also not to scale. These two effects tend to cancel out.
People look at this visualization for what, 60 seconds? But the issue is that objects are zooming around up there for years-to-centuries.[0] The total volume of space swept out is massive.
Invariably the "not to scale" comments always get pointed out every time this is posted, but the temporal distortion (which makes people underestimate collisions) is never mentioned. Unless I mention it[1] of course... ;)
There's a much much better educational ESA video[2] which addresses some of the misconceptions in this thread, found via (of all places) Don Kessler's personal website.
---
If you want an expert perspective on orbital debris (vs..... whatever these HN threads always turn into :D ) I highly recommend you check out NASA Johnson's Orbital Debris Quarterly.[3]
Sources:
[0] What really matters is altitude as this graph shows: https://commons.wikimedia.org/wiki/File:Orbital_Debris_Lifet...
[1] https://news.ycombinator.com/item?id=33210261
[2] As this video points out, collisions scale as density squared, which is why all major collisions have happened near 80 degrees latitude: http://www.youtube.com/watch?v=RvZ3Lr-Tj6A
[3] https://www.orbitaldebris.jsc.nasa.gov/quarterly-news/
Some kind of a relative velocity at the closest approach or a collision probability overlay would be way more useful to have than proper scale. That would make it immediately clear that lazy well-kept orbits like GEO are much safer than e.g. 567km SSO at the poles. Or some color coding for the apparent magnitude.
While I totally agree with the logic, this particular visualization might mislead unsuspecting viewers into believing that our LEO is almost fully saturated. In reality, the satellites are so small that they would miss each other even if placed on the same orbit.
A true-to-scale visualization would however be entirely misleading for everyone since it would be completely empty. Just look up in the sky at a clear sky. You would hardly see a single satelite and a visualization on a computer screen would show even less due to pixel size.
Actually the Kesler syndrome, a space debriss cascade is a very real threat and a real concern. I suggest an interview with the commander of the space control quadron in a radiolab episode "Little Big Questions"
> the Kesler syndrome, a space debriss cascade is a very real threat and a real concern
It’s also widely misunderstood.
The risk is in trashing specific orbits. Below 600 km, that would mean certain orbits are too polluted to use for a few months to years. (A dense, compact object above 600 km could stay lofted for decades to over a century. But again, only within a predictable volume.)
That's true but not because the objects are massive. It's because they fly very fast and there's limited traffic management.
We risk solving the wrong problem due to bad visualisations of the situation.
It's actually mostly because we allow objects to fly too high. Small height differences have a huge difference in orbital lifetime (and therefore risk).
https://commons.wikimedia.org/wiki/File:Orbital_Debris_Lifet...
well... Out sky is full of satellites. Granted, there's a lot of empty space in between. But ask any (hobby) astronomer and they'll start a rant about starlink :-P
If anyone is curious, as I was, about the large red shapes on the map, those are the beams of the object tracking/measurement sites. They correlate with the maps at [0]. I was actually pretty blown away when I started reading that page. Apparently those stations can measure <10cm-sized debrisin orbit. What?! Amazing.
[0] https://leolabs.space/radars/
There are "beams" and "instruments". Does anyone know what the distinction is?
The instrument is the particular radar. They usually have two at each location. Each radar is essentially a linear phased array that creates multiple possible beam locations in the radar plane. They light up a beam as a satellite passes through in order to collect measurements. TLDR an instrument has multiple beams.
Ok so there should be "beams" coming from each "instrument"? I didn't see that, but some of the sites are inactive at the moment.
For those who don't know, Leo Labs operates a commercial version of NORAD radar sites that track satellites and debris.
If you're a satellite operator looking to avoid conjunctions, then buying additional measurements helps reduce uncertainty (which is often needed in order to decide if you should conduct a maneuver).
In other words this deliberate deception is a sales pitch
Almost every single active satellite that I click is a Starlink satellite. Amazing how much SpaceX has gotten up there.
And all those were launched on Falcon 9 rockets, with I think only two launch failures ever.
Three now, Starlink Group 9-3 launch failed in July last year. After the failure, the launch hold was cleared in 13 days, which has to be a record of some sort.
If you zoom in, about one in 20 is tumbling around path randomly, and its description is “Rocket body”. But it’s not on “Debris” layer. I wonder why it doesn’t qualify for debris if it looks likely uncontrollable.
Just a reminder to everybody that we are competitively sprinting towards the brick wall of Kessler Syndrome by building out mega-constellations between about 600km and 1600km, sacrificing humanity's future in order to save a small amount of money right now using lower altitude orbits.
Even Starlink is arguably flying too high, but the attempt to compete with them at 1000km where satellites will be causing secondary and tertiary debris events for literally millennia, makes that look sensible.
> sacrificing humanity's future in order to save a small amount of money right now using lower altitude orbits
Kessler is more analogous to pollution than a brick wall. Specific orbits get trashed by a cascade, not the entire sky.
Specific orbits (732km with a 28 degree inclination and 130 degree longitude of the ascending node), but impacts also instantaneously spread debris out over anything close to any of those numbers (700-760, 27-29, 125-135); most debris get spread not in a normal distribution but in a bimodal distribution between the orbital elements of the two impactors, with an additional perimeter of debris kicked out with some random modest dV in every direction from the explosion according to how much impact energy they absorbed. To start with.
But then, debris start to decay, and they decay unevenly, polluting all orbits lower than that. As this debris spreads to a crowded lower orbit it generates additional collisions.
Orbits are cleared to lower orbits according to mass cross section at roughly 10x the rate for every 100km altitude drop. So everything that decays from an accumulation of higher orbits has to eventually pass through a 300km circular orbit, but it's relatively safe because it spends so little time there.
Going full exponential cascade at 1000km might increase the number of impactors by a millionfold, though, which then proceed to rain down over the years on lower orbits.
How is Starlink flying too high? Their orbital decay is something like 5 years right?
Starlink is just under 600km in order to target a specific voluntary threshold of 25 year decay. Most of their finished birds are going to make around 5 years without propulsion or impacts.
Three things about that -
Profitability generates competition, which may or may not respect precedent. Right now Starlink is only really worried about collisions with other parts of Starlink. We cannot afford a Starlink-inspired future to happen at 600km.
Debris generating events can spin out an object with much higher cross sectional mass than an intact satellite. Think of it in terms of what we use drag for on Earth, like a kid building kites. A heavy metal bolt works worse as a kite than a long thin panel.
These calendar decay timelines are blind to density. If there are a billion satellites with a natural lifespan of 5 years flying at 551km then they are going to go into an exponential cascade in a matter of weeks. If you plan to launch very large constellations, you need very fast decay timelines to keep that safe. It is much safer at very low altitude. There is decay 'room' for >10x as many satellites at 300km as at 400km, and >10x as many at 400km as at 500km, and >10x as many at 500km as 600km.
...
It would also be nice to set aside something for manned spaceflight. Unlike with a satellite collision, if a pressure vessel gets penetrated everybody dies and nobody wants to go back. The ISS and Tianhe are going to have to deal with debris risk slowly raining down from a collision at 971km.
This reminds me - I've been looking for an app, website or tool that can predict or visualize the location of any satellite up to a week out. Most softwares show only the intersection times of predicted orbits with fixed locations on earth, i.e. for telescope visibility.
The visualisation is cool. I've never seen the debris fields visualized before. They look like scars. Might be neat to see a viz including the geo synchronous and sun synchronous orbits. Should show up as seemingly dense, but far away.
Those large red blobs are not visualizations of debris fields. You can toggle them off as "instruments", and debris is actually toggled off by default.
Then what do the large red blobs signify? Individually tracked pieces of debris are indeed a different layer.
> The Amazon CloudFront distribution is configured to block access from your country.
This is great! Is there a way to set the visualization to the present moment and real-time?
If you're looking for something real-time, I'd recommend checking out NASA's "Eyes on the Solar System" visualizer (not as comprehensive but still pretty cool):
https://eyes.nasa.gov/apps/solar-system/#/earth
Any visualization representing real time and the present moment would be inaccurate. Tracking data can sometimes be several days old.
Set speed to "1" for realtime (I assume)
Scale is important here. On this example you see satellites coming in close to each other and even clipping.
In reality theyre so small that it makes this look 100x worse than it actually is
Nice to see United Kingdom using a predictable trajectory. Dismayed by so many other nations just crapping all over the planet without consideration though. The lack of foresight is frustrating.
It's just because a very significant amount of UK satellites are OneWeb Internet satellites.
They're not really crapping all over. Orbits at different altitudes rotate around the planet from precession so any satellites spread out randomly over time.
What makes a trajectory unpredictable? Noisy TLEs?
This is really nice! I wish there was a Starlink on/off layer switch, though. Since there are so many Starlink satellites.
That's the debris toggle, I guess
SCNR
> That's the debris toggle, I guess
No, unfortunately I don't think so. Startlinks are there even when you "disable debris".
Instinctively I know the scale is off and changes the perception of this as a visualization, but this is still terribly depressing.
This is the opposite of depressing. Look what we've been able to do! Each of those have/had a purpose and reason for being there and we've gotten tremendous benefit from satellites in space.
Don't miss out on zooming in, each one is visualized so you can tell the non Starlink ones apart.
How accurate is this . And where is our space station
In the search box, input "ISS" and filter by perigee (min: 380; max: 500). You should see the name of one of the modules of the ISS, such as "ISS (Zarya)" [0] or "ISS (Nauka)" [1]. If you can't find it on the visualisation at first, you can get its current location at https://isstracker.pl/en .
[0] https://en.wikipedia.org/wiki/Zarya_(ISS_module) [1] https://en.wikipedia.org/wiki/Nauka_(ISS_module)
We have a few [0]. Some others have pointed out ISS, but there's also Tiangong which you can filter for [1] by looking for 48274 (the NORAD ID).
[0]: https://en.wikipedia.org/wiki/List_of_space_stations#Operati...
[1]: https://platform.leolabs.space/visualizations/leo#search=482...
[flagged]
Starlink satellites are in low enough orbit to decay on very short timescales. More worrisome are Russian satellites in high / very long lived orbits that tend to spontaneously explode.
Not just Russian. There have also been a few cases recently where spent Centaur upper stages -- which were thought to have been completely passivated -- broke apart for unknown reasons. These were in a geosynchronous transfer orbit (with apogee near geosynchronous orbit, perigee down near LEO) so the debris won't decay any time soon.
Upper stages breaking apart is kinda expected. It's a rocket, and it has rocket fuel (explosives) on board. Derelict spy satellites, on the other hand, shouldn't be just going kaboom for no reason. But the Russian ones do.
As noted by another poster, prior to the recent ASAT tests, one of the largest sources of junk was old Soviet nuclear-powered satellites leaking coolant and/or having their pressure vessels explode. Mind you these are actual nuclear reactors, not RTGs.
No, all residual fuel (and anything pressurized) should have been vented after the last burn and there shouldn't be anything left on board with enough energy to cause it to break apart.
It's a real mystery.
(May I ask what definition of ‘passivate’ you are applying here? Even allowing for flexibility in the definition or autocorrect, and applying context, I can’t fathom what is intended to be conveyed by ‘upper stages - which were thought to have been completely passivated’)
https://en.wikipedia.org/wiki/Passivation_(spacecraft) ("Passivation (spacecraft)")
And used in context (this context),
> "The incident is the fourth time a Centaur upper stage has broken up since 2018. In the earlier three cases, the breakups created hundreds of pieces of debris, but no known collisions. That has raised questions about a potential design flaw with the stage or a failure to “passivate” the stage by venting propellant tanks and draining batteries, removing energy that could cause a breakup."
https://spacenews.com/faa-to-complete-orbital-debris-upper-s...
Thanks! I will update my word definitions search to include context keywords instead of ordinary dictionaries :)
Is "spontaneously explode" supposed to be a joke about how Russia will use them as bombs, or are they actually poorly designed?
They actually explode.
https://spacenews.com/low-intensity-explosion-caused-russian...
To be fair the article also said it could have been a collision, even if it isn't super likely.
It's not the only one, just the most recent. A collision can't be ruled out, but there is a frequent tendency of old, retired Russian satellites just exploding for no reason:
https://en.wikipedia.org/wiki/List_of_space_debris_producing...
Before the Chinese A-Sat weapon tests, the #1 source of space junk was radioactive coolant leaking from old Soviet nuclear reactors in space (not RTGs, literally nuclear reactors)
This is true! Had no idea!
"The Soviet Union has been flying nuclear power sources in space since about 1965. For the most part these nuclear power sources have been low-power nuclear reactors using a thermoelectric conversion principle."
https://ntrs.nasa.gov/citations/19900051140
The thing 'rebelgecko is alluding to is specific, and fascinating! The coolant in these space reactors is a molten metal (low-melting point sodium-potassium eutectic). When they leaked in the space vacuum, the liquid dispersed into a large number of small, metal spherules, which formed rings around Earth. Because the spherules are metallic and smooth, they're (comparatively) easy to track by radar, from Earth.
https://ntrs.nasa.gov/api/citations/20190033494/downloads/20... (pdf) ("The NaK Population: a 2019 Status")
Aside from light pollution they leak radio signals which is starting to impact our ability to make astronomical observations.
https://en.wikipedia.org/wiki/Starlink#Impact_on_astronomy
It may comfort you to hear that the Starlink satellites are tiny in comparison to the vastness of their orbit – the visualization makes them appear larger than they are, so you can see them clearly – and that they’re low enough that they’ll naturally de-orbit and burn up in the atmosphere after about 15 years even without using their maneuvering thrusters.
They’re providing worldwide rural broadband, and according to the FAA they’re doing so in a way that’s careful and responsible about space debris and collision avoidance. Is disgust truly warranted in this case?
Red zones are “instruments” which isn’t defined, but is apparently surface-based observatories.
Stuff like Space Fence.
[flagged]
We've banned this account for using HN for ideological battle about a single topic. This is against the HN guidelines. Please stop registering accounts for posting about this topic and breaking the guidelines. Other community members are noticing this activity and pointing it out to us.
It's more that Golden Dome is taking advantage of the architecture that Starlink has proved to be realistic. It will use separate satellites managed by the Space Development Agency (Tranche 0 consisting of proof of concept stuff launched a while ago
Total coincidence that the founding members of SpaceX and Mars Society were former Star Wars people..
https://en.wikipedia.org/wiki/Citizens%27_Advisory_Council_o...
Pretty much everyone over 50 who had experience in constellations in the 2010s worked on Star Wars.
Sure, that's why satellite constellations were developed. The thing people might not appreciate is that it's still the main driver for these companies to develop them.
> it's still the main driver for these companies to develop them
It’s not. Not by a long shot. Like, OneWeb and Planet Labs are not secretly ABM projects.
It’s a motivation. One that until recently didn’t pay the bills. But it’s never been the motivation for any commercial constellation so far. (Starshield comes close. But I wouldn’t say ABM is even in the top three military motivations for that project.)
[dead]
That's not true. Starlink was developed for its stated purpose. It's a conspiracy pushed by Russian plants that it's for missile defense. A lot of information on that wiki page is made up. Like the constant talk of griffin.
You're saying he didn't accompany Musk on his trips to Russia when he wanted to buy a rocket (before founding SpaceX)?
> he didn't accompany Musk on his trips to Russia when he wanted to buy a rocket (before founding SpaceX)?
Shouldn’t this disprove the hypothesis? If you wanted Musk to build you a constellation, why would you want him to buy a rocket from Russia?
Griffin did not fund SpaceX. He does not have any money. And yes Griffin, among several other people, accompanied Musk to Russia as advisors for his private plan to buy rockets to send a mini-greenhouse to Mars. The failure to make a deal is what precipitated the creation of SpaceX. Elon offered Griffin the position of chief engineer at SpaceX, but Griffin refused.
[flagged]